Implantable miniaturized ultrasonic transducers

Abstract

The present invention comprises an ultrasonic measuring device and method for measuring bone resorption and remodeling using Miniaturized Ultrasonic Transducers. An ultrasonic measuring device for insertion into hard tissue comprises an elongate member with an implant end of the elongate member and an acoustic transducer mounted from the interior of the elongate member at the implant end. The implant end of the ultrasonic measuring device is configured such that the acoustic transducer can measure, when inserted into a hard tissue, variations of the hard tissue using ultrasonic wave propagation. The method of taking measurements of bone resorption and remodeling includes taking measurements of a healthy region and remodeling region of a bone using ultrasonic wave propagation; and calculating the variations in the bone's density and its elasticity along the bone's length a) in the healthy region and b) in the remodeling region.

1 . An ultrasonic measuring device comprising:
 an elongate member including and internal and external surface;   an implant end of the elongate member;   an acoustic transducer mounted from the interior of the elongate member at the implant end;   an input for electrical power operatively connected to the acoustic transducer;   whereby the implant end of the ultrasonic measuring device is configured such that the acoustic transducer can measure, when inserted into a hard tissue, variations of the hard tissue using ultrasonic wave propagation.   
   
   
       2 . The ultrasonic measuring device of  claim 1 , wherein the acoustic transducer is mounted from the interior of the elongate member at the implant end through an auxiliary plug. 
   
   
       3 . The ultrasonic measuring device of  claim 1 , wherein the acoustic transducer can produce an acoustic beam normal to the elongate member in a controlled direction. 
   
   
       4 . The ultrasonic measuring device of  claim 1 , wherein the acoustic transducer is up to about 1 mm in diameter. 
   
   
       5 . The ultrasonic measuring device of  claim 1 , wherein the acoustic transducer includes the capability to operate at a frequency of about 4 MHz. 
   
   
       6 . The ultrasonic measuring device of  claim 1 , wherein the elongate member is configured to operate as an orthopedic screw. 
   
   
       7 . The ultrasonic measuring device of  claim 1 , wherein the elongate member is configured to operate as an external fixator. 
   
   
       8 . The ultrasonic measuring device of  claim 7 , further comprising:
 a plurality of external fixators;   whereby the plurality of external fixators are configured such that the fixators are capable of taking measurements of a healthy region of the hard tissue and a remodeling region of the hard tissue.   
   
   
       9 . The ultrasonic measuring device of  claim 8 , wherein the configuration of the external fixators permits self-calibrating measurements of a healthy region of the hard tissue and a remodeling region of the hard tissue. 
   
   
       10 . An ultrasonic measuring device comprising:
 an elongate member;   an implant end of the elongate member;   an acoustic transducer mounted from the interior of the elongate member at the implant end;   a cavity on a non-implant portion of the elongate member;   whereby the device is configured to allow in vitro measurements of hard tissue formation in the cavity using ultrasonic wave propagation.   
   
   
       11 . A method of taking measurements of bone resorption and remodeling comprising:
 taking a measurement of a healthy region of a bone using ultrasonic wave propagation;   taking a measurement of a remodeling region of a bone ultrasonic wave propagation; and   calculating, using factors comprising the healthy region measurement and the remodeling region measurement, the variations in the bone's density and its elasticity along the bone's length a) in the healthy region and b) in the remodeling region.